This is the 10 round Black Dog magazine for AR15 format .22WMR & .17HMR conversions.Manufactured from tough polycarbonate with mono-bloc nylon feed lips it is fully strippable for cleaning.It is a limited version of the 14 round magazine, identical except for a round limiter stud formed into the follower track.Fits the following rifles and mechanisms:RAYVIN.com .22 WMR (.22 Magnum) AR15 upper (as used on NWCP builds)Garrow Firearms .17HMR upper